Commercial Vs Milspec Vs A5 system

[tx1021]

I currently have a commercial receiver extension on my 11.5" BCM upper with an AGP lower and have been considering switching over to at least a Mil-spec tube or upgrading to the A5 system.

Now my question is will the benefits of switching over to either one of these be worth the costs? As of right now I have a perfectly functioning rifle that I am more than happy with but I am more than open to upgrading if it is worth it.

Thanks for the help.


Also I wasn't sure if this should be in technical or general AR discussions so if it is in the wrong place apologies.

[jonconsiglio]

Is your rifle performing well for you now? (edit - I see that it is) Personally, I'd switch over to a milspec RE, but that's because all of my other rifles have them (or an A5) and I like the ability to switch stocks if I need to. Also, I don't mind the extra durability over a commercial RE either.

If the rifle is running well for you, I don't really see a need to switch, especially since you'll need a new stock as well to fit the milspec/A5 diameter extension.

[HKUSP.40]

What kind of stock do you have now? Just know that if you switch from Commercial to Mil-Spec, you'll have to buy a new stock too.

[tx1021]

What kind of stock do you have now? Just know that if you switch from Commercial to Mil-Spec, you'll have to buy a new stock too.

I'm currently running an IMOD, I think the biggest cost/hassle of going to milspec will be just replacing the stock. Although if I can sell this one it will help offset the costs some.

Edited to add: I shoot with the stock one notch out from fully collapsed right now, the A5 system will have the same LOP as this when fully collapsed with an IMOD correct?

[jonconsiglio]

Edited to add: I shoot with the stock one notch out from fully collapsed right now, the A5 system will have the same LOP as this when fully collapsed with an IMOD correct?

yes, you'll be able to run it with the A5 in the same position. That's where I run my SOPMODs.

[KrampusArms]

Personally, I'd switch over to a milspec RE....... Also, I don't mind the extra durability over a commercial RE either.

Is the milspec really more durable? I know the outside diameter is smaller, but do they have 'thicker' walls?

To the OP, if this is the case, I'd personally get a milspec tube.

[DOA]

Why fix whats not broke ? Is this for range use or duty use?

[kartoffel]

Is the milspec really more durable? I know the outside diameter is smaller, but do they have 'thicker' walls?

To the OP, if this is the case, I'd personally get a milspec tube.

Yes. Commercial receiver extensions are weaker because they have cut threads vs. rolled threads on a regular RE. To make cut threads, you physically remove material, typically on a lathe or NC machine. To make rolled threads, the work is fed through a series of dies that displaces the metal into the thread form without cutting or removing.

The cold-working involved in rolling threads makes the threads stronger and less prone to cracking or stripping.
http://www.ebcind.com/images/subpages/capabilities/image-threadRolling2.jpg

Rolling the threads also helps avoid the stress riser where the commercial threads cut into the RE. Commercial tubes aren't bigger because they were trying to making the tube stronger: they have to start out at the final thread profile OD.

http://www.ottawaproducts.com/images/guidelines%20pics/Wire-Diameters-Cut-Rolled.gif

[tx1021]

Why fix whats not broke ? Is this for range use or duty use?

It is my primary HD weapon, but no, not a duty weapon. However, I don't think that is any reason to have sub-par equipment if you know what I mean.




Yes. Commercial receiver extensions are weaker because they have cut threads vs. rolled threads on a regular RE. To make cut threads, you physically remove material, typically on a lathe or NC machine. To make rolled threads, the work is fed through a series of dies that displaces the metal into the thread form without cutting or removing.


Thanks for the explanation. So do you think it's worth replacing a reliably running commercial re with a mil-spec re based on the strength differences?

[Col_Crocs]

Thanks for the explanation. So do you think it's worth replacing a reliably running commercial re with a mil-spec re based on the strength differences?

That's what i did. If you dont mind the cost of completely switching over RE kit, stock etc, i say go for it. I would go ahead and just get the A5 as well.

[KrampusArms]

Yes. Commercial receiver extensions are weaker because they have cut threads vs. rolled threads on a regular RE. To make cut threads, you physically remove material, typically on a lathe or NC machine. To make rolled threads, the work is fed through a series of dies that displaces the metal into the thread form without cutting or removing.

The cold-working involved in rolling threads makes the threads stronger and less prone to cracking or stripping.
http://www.ebcind.com/images/subpages/capabilities/image-threadRolling2.jpg

Rolling the threads also helps avoid the stress riser where the commercial threads cut into the RE. Commercial tubes aren't bigger because they were trying to making the tube stronger: they have to start out at the final thread profile OD.

http://www.ottawaproducts.com/images/guidelines%20pics/Wire-Diameters-Cut-Rolled.gif

Awesome responce. I learned something new, thank you for the diagrams. This is why I love this forum. You guys are on point.

[Casull]

Commercial runs fine. Probably would do fine in messed up conditions, too. What is nice about switching to mil-spec is it is an actual upgrade in more ways than simply more stock options being readily available. Is it a super important upgrade? probably not, but it's not a bad one by any means. It IS a part of the receiver that has a bolt flying into it after all.

To that end, I have a commercial tube on one of my guns and I'm probably not going to switch it. We'll see, though. I like the look of the mil-spec tube.

Recently I e-mailed Vltor about the outer geometry of their stocks between mil-spec and commercial. There is no difference, only in the bore size of the stock.

[jonconsiglio]

Commercial runs fine. Probably would do fine in messed up conditions, too. What is nice about switching to mil-spec is it is an actual upgrade in more ways than simply more stock options being readily available. Is it a super important upgrade? probably not, but it's not a bad one by any means. It IS a part of the receiver that has a bolt flying into it after all.

To that end, I have a commercial tube on one of my guns and I'm probably not going to switch it. We'll see, though. I like the look of the mil-spec tube.

Recently I e-mailed Vltor about the outer geometry of their stocks between mil-spec and commercial. There is no difference, only in the bore size of the stock.

Your commercial may run fine... But, considering most commercial RE's are 6061 and milspec RE's should be 7075, there is a difference. I can't speak for Vltor commercial RE's, but most are 6061.

[Casull]

I meant the Vltor stock sizes, not RE's. Or did I read your reply wrong? :confused:

[jonconsiglio]

I meant the Vltor stock sizes, not RE's. Or did I read your reply wrong? :confused:

I'm assuming that you're using a commercial receiver extension since you're using a commercial stock...

The stock itself, whether milspec or commercial sizing, should perform exactly the same. The receiver extension (buffer tube) on the other hand may not hold up as well. Not only due to the thread cut, but the fact that most commercial RE's are made of 6061 and most RE's that say milspec are 7075. The reason I say "most milspec RE's" is because some say their's is milspec, but that's in size only, not material.

Since 7075 is somewhere in the neighborhood of twice as strong as 6061, that will make a difference in durability. If that difference is noticeable obviously depends on the shooter. Given a choice, I'll always take the more durable product.

What I'm not sure of here is if Vltor's commercial RE is 6061 or not. I would assume it is since most of them are, but I can't say that as fact.

[Failure2Stop]

If you want a milspec RE and stock, it's worth it.
If you really don't care, it isn't.